Red disazo dye and process of making same.



UNITED STATES PATENT! OFFICE.

CONRAD SOHRAUBE AND lVALTER VOIGTLAENDER-TETZN ER, OF LUDWIGS-HAFEN-ON-THE-RHINE, GERMANY, ASSIGNORS TO BADISOHE ANILIN & SODA FABRIK,OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, A COR- PORATION OF GERMANY.

RED DISAZO DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 713,507, dated November11, 1902.

Application filed August 13, 1901. Serial No. 71,919. (No specimens.)

To all whom, it may concern:

Be it known that we, CONRAD SCHRAUBE, a subject of the King of Prussia,German Emperor, and WALTERVOIGTLAENDER-TETZNER, a subject of the King ofSaxony, doctors of philosophy and chemists, residing atLudwigshafen-on-the-Rhine, in the Kingdom of Bavaria, Germany, haveinvented new and useful Improvements in Red Disazo Dyes and Processes ofMaking Same, of which the following is a specification.

Several mixed disazo coloring-matters obtaincd from benzidine andsalicylic acid and a further component have already been described invarious publications. \Ve have now discovered a certain new class ofsuch mixed disazo coloring-111 atters possessing very valuableproperties. The said new class of coloring-matters is obtained accordingto our invention when the intermediate product resulting from thecombination of tetrazodiphenyl with salicylic acid is combined with1-naphtl1ol-3-sulfo-acid or with sulfo-acids which may be regarded asderived from this, but which contain a further sulto group in a betaposition. Also certain amido deriva tives of these acids can be used;but it is the characteristic feature of our invention that this compoundis a naphthalene derivative with a sulfo group in the position three anda hydroxyl group in the position one. The new coloringmatter thusobtained when using the l-naphtholS-sulfo-acid dyes wool from theacid-bath, and if the dyed Wool be then treated with chromic acid abrilliant red, possessing a bluish tinge and consider able fastness tofulling, is obtained. Similarly, also, the coloring-matters obtained byusing the 1.3.6 and 1.3.7 naphthol-disultoacids yield beautiful shadesfast to milling, and these coloringmatters are advantageouslydistinguished from that obtained by using 1.3.8 naphthol-disulfo-acid(one of whose sulfo groups is in an alpha position) by their superiorfastness to light. Amido-naphthol sulfo-acids which contain a sulfogroup in the position three to the hydroXyl group in the position oneand which have an acid residue introduced into the amido group, so thatthe acids no longer have the character of amidonaphthol-sulfo-acids, butmore that of naphthol sulfo-acids, can also be used in carrying out ourinvention. We except, however, aceytl-6-amido-l-naphthol-3-sulfo-acid,the use of which we do not claim for carrying out our invention.Instances of acids of this class are benzoyl-gamma-acid,which may becalled 7 benzoylamido-l-naphthol- 3 -sulfo-acid, also benzol I acid-that is, 6 benzoylamido-l-naphthol-3-sulfo-acidand benzoyl- M-acidthatis, 5-benzoyl-amido-l-naphthol- 8-sulto-acid. The coloring-mattersresulting from the combination of these components with the intermediateproduct from tetrazodiphenyl and salicylic acid are red dyes withconsiderable fastness to milling, and they may be obtained either bycombining the tetrazo compound first with salicylic acid and then withthe other component, or the order of the combination may be inverted.

The following table shows some of the properties of some of thecoloring-matters obtainable according to our invention:

l i i t On addition otl Solution in Sahcyhcacnl C0101 0 On addition ofconthe aqueconcentrated concentrat- Lenmdme Ous 501W hydrochloricggggllatgd caustic ed Sulfuric Solution In alcohol.

tiou. acid. 3 acid, (96%.)

1-naphthol-3-sulfo-acid Blue1'ed Reddisl1-brown Yellow-red solution.Violet Somewhat soluble.

precipitate. 1.3.6 naphthol-disulfoncid Blue-red. Reddish-brownYellow-red solution" Violet Insoluble.

precipitate. Benzoyl-U-amido1-naphthol-3-sulfo-acid. Red Reddish-brownBlue-red solution or Blue Somewhat soluble.

precipitate. precipitate. BenZ0yl-7-amido-1-naphthol-3-sulfo-aoidBlue-red. Violet-btr'own Yellow-red solution Violet Somewhat soluble.

precipi ate. BenzoyLS-amido-i-naphthol-B-sulfo-acid.. Blue-red. Violet-b 11;ocwn Yellow-red solution Violet Somewhat soluble.

precipi a e.

collect it by filtering.

On reduction with zinc-d ust and ammonia they yield benzidine, paraamido salicylic acid, and an amido derivative of thel-naphthol-3-sulfo-acid substance originally employed.

The following examples will serve to further illustrate the nature ofour invention and the manner in which the same may be carried intopractical effect; but the invention is not confined to the saidexamples. The parts are by weight.

Example 1: Prepare a solution of tetrazodiphenyl chlorid in the usualway from one hundred and eighty-four (184) parts of benzidine, sixhundred (600) parts of hydrochloric acid, (containing about thirty percent. of H01,) and one hundred and thirty-eight (138) parts of sodiumnitrite. Run the tetrazo compound into a solution of one hundred andthirty-eight (138) parts of salicylic acid, eight hundred (800) parts ofcalcined soda, and five thousand (5,000) parts of water. Theintermediate product forms in the course of a few hours and separatesout as a yellow to redbrown precipitate. To this add a solution of threehundred and forty-eight (348) parts of 1-naphthol-3.6-disulfo-acid(sodium salt) and one hundred (100) parts of calcined soda in fivethousand (5,000) parts of water. Stir the mixture for about twelve (12)hours, heat it until it boils, precipitate it with common salt, filterwhile hot, press, and dry.

Example 2: Prepare a solution of tetrazodiphenyl chlorid as described inthe foregoing example and run it into a solution of three hundred andforty-eight (348) parts of the sodium salt of 1-naphthol-3.6-disulfo-acid and one thousand (1,000) parts of calcined soda in tenthousand (10,000) parts of water. When the formation of the intermediateproduct is complete, precipitate it with com mon salt and Add it to asolution of one hundred and thirty-eight (138) parts of salicylic acidand two hundred (200) parts of calcined soda in five thousand (5,000)parts of water, to which one hundred and twenty (120) parts ofcaustic-soda lye (containing thirty-five per cent. of NaOH) are furtheradded. Stir the mixture for about twelve (12) hours, then heatit, saltthe coloring-matter out from the hot solution, filter, press, and dry.

Example 3: Prepare the intermediate prodnot from benzidine and salicylicacid, as described in the foregoing Example 1, and to the liquidcontaining this product in suspension add a solution of three hundredand forty-three (343) parts of 5.benzoylamido-1- naphthol-3-sulfo-acidand two hundred (200) parts of calcined soda in five thousand (5,000)parts of water. Stir the mixture for about twelve (12) hours, then saltout, and precipitate the coloring-matter with common salt from the hotsolution, filter, press, and dry.

Now what we claim is- 1. The new disazo coloring-matter such as can beobtained by combining the intermediate substance, obtainable from onemolecular proportion of tetrazo-diphenyl and one molecular proportion ofsalicylic acid, with a hereinbefore-defined 1.naphthol-3-sulfo-acidsubstance which is soluble in water with a bluish-red, to red, color,which solution on the addition of hydrochloric acid yields areddish-brown, to violet-brown, precipitate and on reduction withzinc-dust and ammonia yields benzidine, para-amido-salicylic acid and anamido derivative of the 1.3-naphtholsulfo-acid substance originallyemployed.

2. The new disazo coloring-matter such as can be obtained by combiningthe intermediate substance obtainable from one molecular proportion oftetrazo-diphenyl and one molecular proportion of salicylic acid with1.naphthol-3. 6-disulfo-acid which is soluble in water with a blue-redcolor, which solution on the addition of hydrochloric acid yields areddish-brown precipitate and on reduction with zinc-dust and ammoniayields benzidine, para-amido-salicylic acid and2-amido-l-naphthol-3.6-disulfo-acid.

In testimony whereof we have hereuntoset our hands in the presence oftwo subscribing witnesses.

WVitnesses:

JOHN L. HEINKE, M. SCHUMANN.

